Age / Sex : 12 / F

Chief complaint: For regular check-up, s/p curettage & bone graft in right tibia
What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

(답안은 한 개만 보내주시기 바랍니다)

Courtesy: 홍석주 (Suk Joo Hong), 고려대학교 구로병원 (Korea university Guro hospital)

Osteofibrous dysplasia (OFD), ossifying fibroma

Discussion

Findings:

-       Plain radiography: large, expansile osteolytic lesion with multiple bubble-like foci and marginal sclerotic band at right tibia diaphysis. The lesion is slowly growing over 10 years, especially in the superolateral aspect, with more sclerotic change in the central portion.

-       MRI: large, expansile, multilobulated mass in the right tibia diaphysis, with central location, shows heterogeneous T1 low & T2 high signal intensity and intense peripheral enhancement.

Differential Diagnosis:

1.     OFD like adamantinoma

2.     Fibrous dysplasia

3.     Adamantinoma

Diagnosis:

Osteofibrous dysplasia (OFD)

Discussion:

-       Rare, benign fibro-osseous lesion, considered a fibrovascular defect

-       Age: 0 - 20 yrs

-       General features

: Involvement of diaphysis, tibial anterior cortex (77-92%)

: Intracortical

: Eccentrically expansive

: Predominantly lytic lesion (single focus or multiple bubble-like foci) with/without marginal band of sclerosis

: Bowing deformity, usually anterior

-       MR: T1& T2 low SI

-       No malignant change; recurrence after op.; self limiting nature

-       Pathologically active osteoblasts (+)

References:

1. Kuhn et al. Caffey’s Pediatric Diagnostic Imaging. 10th edition. Mosby.

2. Miller et al. Bone Tumors and Tumor like Conditions: Analysis with Conventional Radiography. Radiology 2008; 246:662–674.

3. Levine et al. Cortical Lesions of the Tibia: Characteristic Appearances at Conventional Radiography. RadioGraphics 2003; 23:157–177.

4. Khana et al. Osteofibrous dysplasia, osteofibrous dysplasia-like adamantinoma and adamantinoma: correlation of radiological imaging features with surgical histology and assessment of the use of radiology in contributing to needle biopsy diagnosis. Skeletal Radiol 2008 37:1077–1084.